c# - Xamarin IOS 加载 View 表单手势事件

Question

我正在 try catch PanGesture 事件，因此当用户用他/她的手指在 View 中的任意位置向右滑动时，例如，RightView 出现，当向左滑动时，LeftView 出现。

我正在使用下面的代码。它来自 Xamarin 文档。我修改了一下。我的“currView”是当前 View 的导出。当我用鼠标在模拟器上滑动时，事件被正确捕获，但是当(在中断指向之后)在

的大括号处单步执行时

    if (recognizer.State != (UIGestureRecognizerState.Cancelled | UIGestureRecognizerState.Failed
    {

代码在它和这个之间循环。

     HandleDrag(gesture))

每个像素一次(我认为)。

我试图触发另一个 View 的加载，但没有找到放置它的位置。我在

    Console.WriteLine ("Here")

在:

    currView.AddGestureRecognizer (gesture);

但每次代码完成循环时，它都会忽略它并结束执行。如何加载下一个 View ？

注释行:

    // NEED TO LOAD ANOTHER VIEW HERE 

显示我想要加载另一个 View 的位置。

这是我的代码

namespace Example_Touch.Screens.iPhone.GestureRecognizers
{
using System;
using System.Drawing;

using MonoTouch.Foundation;
using MonoTouch.UIKit;

public partial class GestureRecognizers_iPhone : UIViewController
{
    private RectangleF originalImageFrame = RectangleF.Empty;
    // The IntPtr and initWithCoder constructors are required for items that need 
    // to be able to be created from a xib rather than from managed code

    public GestureRecognizers_iPhone(IntPtr handle)
        : base(handle)
    {
        Initialize();
    }

    [Export("initWithCoder:")]
    public GestureRecognizers_iPhone(NSCoder coder)
        : base(coder)
    {
        Initialize();
    }

    public GestureRecognizers_iPhone()
        : base("GestureRecognizers_iPhone", null)
    {
        Initialize();
    }

    public override void ViewDidLoad()
    {
        base.ViewDidLoad();


        WireUpDragGestureRecognizer();
    }

    protected void WireUpDragGestureRecognizer()
    {
        // create a new tap gesture
        UIPanGestureRecognizer gesture = new UIPanGestureRecognizer();

        // wire up the event handler (have to use a selector)
        gesture.AddTarget(() => HandleDrag(gesture));
        currView.AddGestureRecognizer (gesture);
    }

    protected void HandleDrag(UIPanGestureRecognizer recognizer)
    {
        PointF offset2 = recognizer.TranslationInView(currView);
        // if it's just began, cache the location of the image


        if (recognizer.State != (UIGestureRecognizerState.Cancelled | UIGestureRecognizerState.Failed
            | UIGestureRecognizerState.Possible))
        {
            Console.WriteLine ("Here");
                            // NEED TO LOAD ANOTHER VIEW HERE
        }

    }
    private void Initialize()
    {
    }
}

Answer 1

来自 Apple 文档:

平移手势是连续的。当允许的最小手指数 (minimumNumberOfTouches) 移动到足以被视为平移时，它开始 (UIGestureRecognizerStateBegan)。当至少按下最小数量的手指移动手指时，它会更改 (UIGestureRecognizerStateChanged)。当所有手指都抬起时结束(UIGestureRecognizerStateEnded)。

检查 UIGestureRecognizerState.Ended 状态，如果出现这种情况，您可以加载另一个 View 。根据您的描述，您似乎可以使用 UISwipeGestureRecognizer 而不是 UIPanGestureRecognizer。 UISwipeGestureRecognizer 是一个离散的手势，因此您不必检查状态，只需以这种方式实现它:

在您的代码中的某处实现处理程序:

private void HandleSwipeRight()
{
    // load another view
    Console.WriteLine("Swipe right.");
}

并在ViewDidLoad()中初始化手势识别器:

UISwipeGestureRecognizer swipeGestureRecognizerRight = new UISwipeGestureRecognizer(HandleSwipeRight);
swipeGestureRecognizerRight.Direction = UISwipeGestureRecognizerDirection.Right;
this.View.AddGestureRecognizer(swipeGestureRecognizerRight);

您可以为不同的方向添加另一个滑动手势识别器。